Minimum Roof Pitch For Michigan Snow Loads

Roof slope equivalents as rise.

Minimum roof pitch for michigan snow loads. This can be accomplished by measuring the number of inches the roof rises vertically for every 12 inches it extends horizontally. Figure 1608 2 for any location in the state of michigan. For example a roof with a 6 inch 12 pitch is one where it rises 6 inches vertically for every 12 inches of the horizontal run. To figure out the load on your roof take the depth of snow in feet and multiply it by the weight of a cubic foot of snow.

Astm b370 minimum 16 oz sq ft and 12 oz sq ft high yield copper for metal sheet roof covering systems. The state has amended the snow load requirements of the 2009 ibc figure 1608 2 and the 2009 irc figure r301 2 5 table r301 2 1 and table. Use our michigan ground snow loads map to easily determine the ground snow load 2009 michigan building code. Roof pitch multiplier table.

Run in degrees and as percentage the minimum roof slope allowed by code for any type of roof is in 12 applicable only to coal tar pitch roof systems. In general determining the pitch of an existing roof is a simple calculation. Degrees to pitch rise in run table. If these issues are addressed during the design stage and the roofing contractor does his job these systems will almost always perform as intended.

The key factors are usually snow loading requirements adequate slope and the use of snow guards when needed. If the snow weighs 10 pounds per cubic foot and there are 1 5 feet on the roof each square foot of the roof is getting 15 pounds of pressure. 12 oz sq ft for preformed metal shingle systems. If you live in the us our snow load calculator compares the total weight on your roof with the permissible load calculated according to the standards issued by the american society of civil engineers regarding the minimum design loads for buildings and other structures asce7 16.

The minimum roof pitch is also subject to the standards set forth by the various building codes used in the respective regions. Metal roofing systems have a good track record of performance in harsh winter environments as long as they are properly designed. If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow. The chief reason for having a roof pitch is to redirect water and snow away from the roof and avoid any percolation that might result from stagnation of water on the roof.